The invention relates to a spoked wheel for tubeless tires, also called tubeless, particularly for motorcycles, cars and similar vehicles. Tubeless tires have been preferred for some time now in the motorcycle industry as well, especially for high-performance motorcycles. It is a known fact that tubeless tires have numerous advantages compared to tires with inner tubes.
Tubeless tires are safer and are not subject to bursting, and because they have no inner tube, this cannot be lacerated. In case of a flat tire, they deflate fairly slowly, making it possible to ride the motorcycle as far as a tire-repair shop.
Furthermore, they are not subject to any sliding or rotation of the tire with respect to the rim, which in the case of tires with inner tubes could cause the valve to tear away from the inner tube. For operation and assembly, tubeless tires require an airtight rim with a special seal profile for the tire bead. For this reason, in most cases, cast or pressed rims are used, almost always with rigid spokes. In fact, because, traditionally, a spoked wheel comprises a rim with through holes to fix the spokes using nipples, it is very difficult to seal the hole area where the fixing nipples are fitted.
Alternatively, e.g. in the patent EP-B-O 143 394, rims for spoked wheels have been presented with the spoke fitting seats arranged on the edges of the rim, so as to allow fitting tubeless tires. The rim of the patent EP-B-O 143 394 has considerably thick sides, because it also has to contain the spoke seats, and is therefore heavier than standard type rims. Furthermore, manufacturing the rim is also more difficult with increase in production costs.
Another problem regarding the rims currently in use for spoked wheels, and in particular for off-road, enduro or supermotard motorcycle competitive use, is that of the relevant lack of sturdiness of the rim. In fact, the traditional manufacture of spoked wheels for motorcycles envisages that the rim be made of aluminum alloy by extrusion with subsequent rolling until a round element is obtained that is then closed by welding.
The structure of the rims obtained in this way is not sturdy enough to withstand off-road stresses, and therefore often breaks. On the other hand, spoked wheels are preferred in the off-road sector for their greater elasticity and their ability to withstand the stresses of off-road, enduro, motocross riding, etc.